The present invention relates generally to biosynthetic processes, and more specifically to organisms having adipate, hexamethylenediamine, 6-aminocaproic acid and caprolactam biosynthetic capability.
Adipic acid, a dicarboxylic acid, has a molecular weight of 146.14. It can be used is to produce nylon 6,6, a linear polyamide made by condensing adipic acid with hexamethylenediamine. This is employed for manufacturing different kinds of fibers. Other uses of adipic acid include its use in plasticizers, unsaturated polyesters, and polyester polyols. Additional uses include for production of polyurethane, lubricant components, and as a food ingredient as a flavorant and gelling aid.
Historically, adipic acid was prepared from various fats using oxidation. Some current processes for adipic acid synthesis rely on the oxidation of KA oil, a mixture of cyclohexanone, the ketone or K component, and cyclohexanol, the alcohol or A component, or of pure cyclohexanol using an excess of strong nitric acid. There are several variations of this theme which differ in the routes for production of KA or cyclohexanol. For example, phenol is an alternative raw material in KA oil production, and the process for the synthesis of adipic acid from phenol has been described. The other versions of this process tend to use oxidizing agents other than nitric acid, such as hydrogen peroxide, air or oxygen.
In addition to hexamethylenediamine (HMDA) being used in the production of nylon-6,6 as described above, it is also utilized to make hexamethylene diisocyanate, a monomer feedstock used in the production of polyurethane. The diamine also serves as a cross-linking agent in epoxy resins. HMDA is presently produced by the hydrogenation of adiponitrile.
Caprolactam is an organic compound which is a lactam of 6-aminohexanoic acid (ε-aminohexanoic acid, 6-aminocaproic acid). It can alternatively be considered cyclic amide of caproic acid. One use of caprolactam is as a monomer in the production of nylon-6. Caprolactam can be synthesized from cyclohexanone via an oximation process using hydroxylammonium sulfate followed by catalytic rearrangement using the Beckmann rearrangement process step.
Methods for effectively producing commercial quantities of compounds such as hexamethylenediamine, 6-aminocaproic acid, levulinic acid and carpolactamare described herein and include related advantages.